The present application finds particular application in parking brake systems in vehicles, particularly involving pneumatic parking brake systems. However, it will be appreciated that the described technique may also find application in other brake control systems, other valve actuation systems, or other pneumatic control systems.
Conventional single-motion parking brake release mechanisms suffer from many drawbacks, including unintentional parking brake release, which can cause a vehicle to roll unexpectedly and cause injury and/or property damage. For instance, such systems typically employ a plunger knob that an operator pulls outward to actuate the parking brake system. When the operator wants to release the parking brake, the operator pushes the plunger knob inward to a released position, which permits air to be supplied to a parking brake system and causes the parking brake to be deactivated. However, using such an arrangement increases the occurrence of inadvertent or accidental brake release. For instance, an operator or occupant may inadvertently depress the knob into a released position; a pet that travels with the operator in the cab of his truck may depress the knob into a released position when looking out through the windshield, etc. In these cases, if the release of the parking brake is not immediately noticed, the vehicle can roll away and cause damage to property or worse, injury to people.
The present innovation provides a new and improved parking brake release system, which overcomes the above-referenced problems and others.